[arm] Eliminate OperandConverter Float32 and Float64 register methods.

src/compiler/instruction.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_INSTRUCTION_H_
 #define V8_COMPILER_INSTRUCTION_H_
 
 #include <deque>
 #include <iosfwd>
 #include <map>
@@ skipping 421 matching lines @@
     DCHECK(IsRegister());
     return Register::from_code(register_code());
   }
 
   FloatRegister GetFloatRegister() const {
     DCHECK(IsFloatRegister());
     return FloatRegister::from_code(register_code());
   }
 
   DoubleRegister GetDoubleRegister() const {
-    // TODO(bbudge) Tighten this test to IsDoubleRegister when all code
-    // generators are changed to use the correct Get*Register method.
+    // On platforms where FloatRegister, DoubleRegister, and Simd128Register
+    // are all the same type, it's convenient to treat everything as a
+    // DoubleRegister, so be lax about type checking here.
     DCHECK(IsFPRegister());
     return DoubleRegister::from_code(register_code());
   }
 
   Simd128Register GetSimd128Register() const {
     DCHECK(IsSimd128Register());
     return Simd128Register::from_code(register_code());
   }
 
   LocationKind location_kind() const {
@@ skipping 1026 matching lines @@
 
 
 std::ostream& operator<<(std::ostream& os,
                          const PrintableInstructionSequence& code);
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INSTRUCTION_H_